Util


1   /* Copyright 2004-2005 Sun Microsystems, Inc.  All rights reserved.  You may not modify, use, reproduce, or distribute this software except in compliance with the terms of the License at: http://developer.sun.com/berkeley_license.html
2   $Id: Util.java,v 1.2 2005/03/23 14:49:22 jenniferb Exp $  */
3   
4   package com.sun.j2ee.blueprints.catalog.validator;
5   
6   import javax.faces.FactoryFinder;
7   import javax.faces.application.Application;
8   import javax.faces.application.ApplicationFactory;
9   import javax.faces.component.UIComponent;
10  import javax.faces.context.FacesContext;
11  import javax.faces.el.MethodBinding;
12  import javax.faces.el.ValueBinding;
13  import java.util.Locale  ;
14  
15  /**
16   * This class provides common functionality used by
17   * other classes.
18   */
19  
20  public class Util extends Object   {
21      
22      /**
23       * This array contains attributes that have a boolean value in JSP,
24       * but have have no value in HTML.  For example "disabled" or
25       * "readonly". <P>
26       *
27       * @see renderBooleanPassthruAttributes
28       */
29      private static String   booleanPassthruAttributes[] = {
30  
31          "disabled",
32          "readonly",
33          "ismap"
34  
35      };
36  
37      /**
38       * This array contains attributes whose values are rendered
39       * straight to the content.  This array should only contain
40       * attributes that require no interpretation by the renderer.  If an
41       * attribute requires interpretation by a renderer, it should be
42       * removed from this array.<P>
43       *
44       * @see renderPassthruAttributes
45       */
46  
47      private static String   passthruAttributes[] = {
48  
49          "accesskey",
50          "alt",
51          "cols",
52          "height",
53          "lang",
54          "longdesc",
55          "maxlength",
56          "onblur",
57          "onchange",
58          "onclick",
59          "ondblclick",
60          "onfocus",
61          "onkeydown",
62          "onkeypress",
63          "onkeyup",
64          "onload",
65          "onmousedown",
66          "onmousemove",
67          "onmouseout",
68          "onmouseover",
69          "onmouseup",
70          "onreset",
71          "onselect",
72          "onsubmit",
73          "onunload",
74          "rows",
75          "size",
76          "tabindex",
77          "title",
78          "style",
79          "width",
80          "dir",
81          "rules",
82          "frame",
83          "border",
84          "cellspacing",
85          "cellpadding",
86          "summary",
87          "bgcolor",
88          "usemap",
89          "enctype",
90          "accept-charset",
91          "accept",
92          "target",
93          "onsubmit",
94          "onreset"
95      };
96  
97  
98      private static long id = 0;
99  
100     private Util() {
101         throw new IllegalStateException  ();
102     }
103 
104     /**
105      * Loads the class of the specified <code>name</code> from the current thread.
106      */
107     public static Class   loadClass(String   name) throws ClassNotFoundException   {
108         ClassLoader   loader =
109             Thread.currentThread().getContextClassLoader();
110         if (loader == null) {
111             return Class.forName(name);
112         } else {
113             return loader.loadClass(name);
114         }
115     }
116 
117     /**
118      * Generates a new identifier currently used to uniquely identify
119      * components.
120      */
121     public static synchronized String   generateId() {
122         if (id == Long.MAX_VALUE) {
123             id = 0;
124         } else {
125             id++;
126         }
127         return Long.toHexString(id);
128     }
129 
130     /**
131      * Returns a Locale instance using the following algorithm: <P>
132      *
133      * <UL>
134      *
135      * <LI>
136      *
137      * If this component instance has an attribute named "bundle",
138      * interpret it as a model reference to a LocalizationContext
139      * instance accessible via FacesContext.getModelValue().
140      *
141      * </LI>
142      *
143      * <LI>
144      *
145      * If <code>FacesContext.getModelValue</code> returns a 
146      * <code>LocalizationContext</code>
147      * instance, return its Locale.
148      *
149      * </LI>
150      *
151      * <LI>
152      *
153      * If <code>FacesContext.getModelValue</code> doesn't return a
154      * <code>LocalizationContext</code>, return the <code>FacesContext</code>
155      * instance's <code>Locale</code>.
156      *
157      * </LI>
158      *
159      * </UL>
160      */
161     public static Locale  
162         getLocaleFromContextOrComponent(FacesContext context,
163                                         UIComponent component) {
164         Locale   result = null;
165         String   bundleName = null, bundleAttr = "bundle";
166 
167     // verify our component has the proper attributes for bundle.
168         if (null !=
169             (bundleName = (String  ) component.getAttributes().get(bundleAttr))) {
170             // verify there is a Locale for this modelReference
171             javax.servlet.jsp.jstl.fmt.LocalizationContext locCtx = null;
172             if (null != (locCtx =
173                 (javax.servlet.jsp.jstl.fmt.LocalizationContext)
174                 (Util.getValueBinding(bundleName)).getValue(context))) {
175                 result = locCtx.getLocale();
176             }
177         }
178         if (null == result) {
179             result = context.getViewRoot().getLocale();
180         }
181         return result;
182     }
183 
184     /**
185      * Renders any boolean "passthru" attributes.
186      * <P>
187      *
188      * @see passthruAttributes
189      */
190     public static String   renderBooleanPassthruAttributes(FacesContext context,
191                                                          UIComponent component) {
192         int i = 0, len = booleanPassthruAttributes.length;
193         String   value;
194         boolean thisIsTheFirstAppend = true;
195         StringBuffer   renderedText = new StringBuffer  ();
196     
197         for (i = 0; i < len; i++) {
198             if (null != (value = (String  )
199                 component.getAttributes().get(booleanPassthruAttributes[i]))) {
200                 if (thisIsTheFirstAppend) {
201                     // prepend ' '
202                     renderedText.append(' ');
203                     thisIsTheFirstAppend = false;
204                 }
205                 if (Boolean.valueOf(value).booleanValue()) {
206                     renderedText.append(booleanPassthruAttributes[i] + ' ');
207                 }
208             }
209         }
210         return renderedText.toString();
211     }
212 
213     /**
214      * Renders any "passthru" attributes, where we simply just output the
215      * raw name and value of the attribute.  This method is aware of the
216      * set of HTML4 attributes that fall into this bucket.  Examples are
217      * all the javascript attributes, alt, rows, cols, etc.  <P>
218      *
219      * @return the rendered attributes as specified in the component.
220      *         Padded with leading and trailing ' '.  If there are no passthru
221      *         attributes in the component, return the empty String.
222      *
223      * @see passthruAttributes
224      */
225 
226 
227     public static String   renderPassthruAttributes(FacesContext context,
228                                                   UIComponent component) {
229         int i = 0, len = passthruAttributes.length;
230         String   value;
231         boolean thisIsTheFirstAppend = true;
232         StringBuffer   renderedText = new StringBuffer  ();
233 
234         for (i = 0; i < len; i++) {
235             if (null != (value = (String  )
236                 component.getAttributes().get(passthruAttributes[i]))) {
237                 if (thisIsTheFirstAppend) {
238                     // prepend ' '
239                     renderedText.append(' ');
240                     thisIsTheFirstAppend = false;
241                 }
242                 renderedText.append(passthruAttributes[i] + "=\"" + value +
243                                     "\" ");
244             }
245         }
246 
247         return renderedText.toString();
248     }
249 
250     /**
251      * Returns the <code>ValueBinding</code> used to calculate the value
252      * for the specified attribute or property.
253      */
254     public static ValueBinding getValueBinding(String   valueRef) {
255         ApplicationFactory af = (ApplicationFactory)
256             FactoryFinder.getFactory(FactoryFinder.APPLICATION_FACTORY);
257         Application a = af.getApplication();
258         return (a.createValueBinding(valueRef));
259     }
260 
261     /**
262      * Creates a new <code>ConstantMethodBinding</code> object.
263      */
264     public static MethodBinding createConstantMethodBinding(String   outcome) {
265         return new ConstantMethodBinding(outcome);
266     }
267 
268 
269 } // end of class Util
270 
271
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